Ready to Launch

byDean Sigleron11/07/2009

LaunchPoint Technologies, Inc. announces the highest power to weight ratio of any known electric motor – seven horsepower for 1.4 pounds (635 grams) or five pounds per horsepower. As a comparison, the tiny Neutrino outrunner by Steve Neu of Neumotors weighs 14 grams and puts out 125 watts, peak. That would add up to 784 grams at 7 horsepower if that motor were scaled up to match the output of the LaunchPoint unit. The LaunchPoint motor is not only lightweight, but surprisingly small, scaling only six inches in diameter and one inch in thickness. It is composed of a great deal of carbon fiber in its plate-like structure.

The ultra-compact, lightweight LaunchPoint motor.

Behind this astonishing power output is the use of a Halbach array, “an arrangement of permanent magnets that augments the magnetic field on one side of the array while cancelling the field to near zero on the other side,” according to Wikipedia. The effect of the array is powerful enough to permit its use in linear accelerators.

Conceptual Drawing of Halbach Array.

To test the array yourself, try this link, which provides step-by-step instructions on making your own Halbach array refrigerator magnet.

CAFE Foundation personnel have speculated about using the motor as an aircraft brake, able to be controlled differentially on main wheels to automatically assist maintaining a straight takeoff path, or being ramped up to speed to reduce tire wear on landings. The wheel motor/brake could possibly be used to augment takeoff power for STOL craft.